[GAP Forum] computing the structure of a big imprimitive permgroup

[Dmitrii Pasechnik]

Dear Forum,
I have a permutation group G on 6^4 points, with a maximal imprimitivity
block system B with blocks of size 6.
The action on these blocks contains Alt(6^3), that is,
the base for the StabChain for G will be long, at least about 6^3.
I try to compute the StabChain, but it seems to take forever to complete.

I would like to find the kernel of the action of G on B.
(or at least |G|)
Any tips as to how this can be best accomplished?

Thanks,
Dima